ci: add php 8.4 to continuous integration workflow

Author: carlalexander

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-versions: ['7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
+        php-versions: ['7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
     steps:
       - name: Checkout code
         uses: actions/checkout@v4